mesa: also bump version in Makefile.am and configure.ac to 9.0

Signed-off-by: Brian Paul <brianp@vmware.com>
diff --git a/configure.ac b/configure.ac
index 3355488..12a9a74 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,7 +6,7 @@
 m4_divert_once([HELP_END], [
 See docs/autoconf.html for more details on the options for Mesa.])
 
-AC_INIT([Mesa], [8.1.0],
+AC_INIT([Mesa], [9.0.0],
     [https://bugs.freedesktop.org/enter_bug.cgi?product=Mesa])
 AC_CONFIG_AUX_DIR([bin])
 AC_CANONICAL_HOST